/*
 * wpa_supplicant/hostapd control interface library
 * Copyright (c) 2004-2007, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"

#ifdef CONFIG_CTRL_IFACE

#ifdef CONFIG_CTRL_IFACE_UNIX
#include <sys/un.h>
#endif /* CONFIG_CTRL_IFACE_UNIX */

#include "wpa_ctrl.h"
#include "common.h"


#if defined(CONFIG_CTRL_IFACE_UNIX) || defined(CONFIG_CTRL_IFACE_UDP)
#define CTRL_IFACE_SOCKET
#endif /* CONFIG_CTRL_IFACE_UNIX || CONFIG_CTRL_IFACE_UDP */


/**
 * struct wpa_ctrl - Internal structure for control interface library
 *
 * This structure is used by the wpa_supplicant/hostapd control interface
 * library to store internal data. Programs using the library should not touch
 * this data directly. They can only use the pointer to the data structure as
 * an identifier for the control interface connection and use this as one of
 * the arguments for most of the control interface library functions.
 */
struct wpa_ctrl {
#ifdef CONFIG_CTRL_IFACE_UDP
    int s;
    struct sockaddr_in local;
    struct sockaddr_in dest;
    char *cookie;
#endif /* CONFIG_CTRL_IFACE_UDP */
#ifdef CONFIG_CTRL_IFACE_UNIX
    int s;
    struct sockaddr_un local;
    struct sockaddr_un dest;
#endif /* CONFIG_CTRL_IFACE_UNIX */
#ifdef CONFIG_CTRL_IFACE_NAMED_PIPE
    HANDLE pipe;
#endif /* CONFIG_CTRL_IFACE_NAMED_PIPE */
};


#ifdef CONFIG_CTRL_IFACE_UNIX

struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
{
    struct wpa_ctrl *ctrl;
    static int counter = 0;
    int ret;
    size_t res;
    int tries = 0;

    ctrl = os_malloc(sizeof(*ctrl));
    if (ctrl == NULL)
        return NULL;
    os_memset(ctrl, 0, sizeof(*ctrl));

    ctrl->s = socket(PF_UNIX, SOCK_DGRAM, 0);
    if (ctrl->s < 0) {
        os_free(ctrl);
        return NULL;
    }

    ctrl->local.sun_family = AF_UNIX;
    counter++;
try_again:
    ret = os_snprintf(ctrl->local.sun_path, sizeof(ctrl->local.sun_path),
            "/tmp/wpa_ctrl_%d-%d", getpid(), counter);
    if (ret < 0 || (size_t) ret >= sizeof(ctrl->local.sun_path)) {
        close(ctrl->s);
        os_free(ctrl);
        return NULL;
    }
    tries++;
    if (bind(ctrl->s, (struct sockaddr *) &ctrl->local,
                sizeof(ctrl->local)) < 0) {
        if (errno == EADDRINUSE && tries < 2) {
            /*
             * getpid() returns unique identifier for this instance
             * of wpa_ctrl, so the existing socket file must have
             * been left by unclean termination of an earlier run.
             * Remove the file and try again.
             */
            unlink(ctrl->local.sun_path);
            goto try_again;
        }
        close(ctrl->s);
        os_free(ctrl);
        return NULL;
    }

    ctrl->dest.sun_family = AF_UNIX;
    res = os_strlcpy(ctrl->dest.sun_path, ctrl_path,
            sizeof(ctrl->dest.sun_path));
    if (res >= sizeof(ctrl->dest.sun_path)) {
        close(ctrl->s);
        os_free(ctrl);
        return NULL;
    }
    if (connect(ctrl->s, (struct sockaddr *) &ctrl->dest,
                sizeof(ctrl->dest)) < 0) {
        close(ctrl->s);
        unlink(ctrl->local.sun_path);
        os_free(ctrl);
        return NULL;
    }

    return ctrl;
}


void wpa_ctrl_close(struct wpa_ctrl *ctrl)
{
    unlink(ctrl->local.sun_path);
    close(ctrl->s);
    os_free(ctrl);
}

#endif /* CONFIG_CTRL_IFACE_UNIX */


#ifdef CONFIG_CTRL_IFACE_UDP

struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
{
    struct wpa_ctrl *ctrl;
    char buf[128];
    size_t len;

    ctrl = os_malloc(sizeof(*ctrl));
    if (ctrl == NULL)
        return NULL;
    os_memset(ctrl, 0, sizeof(*ctrl));

    ctrl->s = socket(PF_INET, SOCK_DGRAM, 0);
    if (ctrl->s < 0) {
        perror("socket");
        os_free(ctrl);
        return NULL;
    }

    ctrl->local.sin_family = AF_INET;
    ctrl->local.sin_addr.s_addr = htonl((127 << 24) | 1);
    if (bind(ctrl->s, (struct sockaddr *) &ctrl->local,
                sizeof(ctrl->local)) < 0) {
        close(ctrl->s);
        os_free(ctrl);
        return NULL;
    }

    ctrl->dest.sin_family = AF_INET;
    ctrl->dest.sin_addr.s_addr = htonl((127 << 24) | 1);
    ctrl->dest.sin_port = htons(WPA_CTRL_IFACE_PORT);
    if (connect(ctrl->s, (struct sockaddr *) &ctrl->dest,
                sizeof(ctrl->dest)) < 0) {
        perror("connect");
        close(ctrl->s);
        os_free(ctrl);
        return NULL;
    }

    len = sizeof(buf) - 1;
    if (wpa_ctrl_request(ctrl, "GET_COOKIE", 10, buf, &len, NULL) == 0) {
        buf[len] = '\0';
        ctrl->cookie = os_strdup(buf);
    }

    return ctrl;
}


void wpa_ctrl_close(struct wpa_ctrl *ctrl)
{
    close(ctrl->s);
    os_free(ctrl->cookie);
    os_free(ctrl);
}

#endif /* CONFIG_CTRL_IFACE_UDP */


#ifdef CTRL_IFACE_SOCKET
int wpa_ctrl_request(struct wpa_ctrl *ctrl, const char *cmd, size_t cmd_len,
        char *reply, size_t *reply_len,
        void (*msg_cb)(char *msg, size_t len))
{
    struct timeval tv;
    int res;
    fd_set rfds;
    const char *_cmd;
    char *cmd_buf = NULL;
    size_t _cmd_len;

#ifdef CONFIG_CTRL_IFACE_UDP
    if (ctrl->cookie) {
        char *pos;
        _cmd_len = os_strlen(ctrl->cookie) + 1 + cmd_len;
        cmd_buf = os_malloc(_cmd_len);
        if (cmd_buf == NULL)
            return -1;
        _cmd = cmd_buf;
        pos = cmd_buf;
        os_strlcpy(pos, ctrl->cookie, _cmd_len);
        pos += os_strlen(ctrl->cookie);
        *pos++ = ' ';
        os_memcpy(pos, cmd, cmd_len);
    } else
#endif /* CONFIG_CTRL_IFACE_UDP */
    {
        _cmd = cmd;
        _cmd_len = cmd_len;
    }

    if (send(ctrl->s, _cmd, _cmd_len, 0) < 0) {
        os_free(cmd_buf);
        return -1;
    }
    os_free(cmd_buf);

    for (;;) {
        tv.tv_sec = 2;
        tv.tv_usec = 0;
        FD_ZERO(&rfds);
        FD_SET(ctrl->s, &rfds);
        res = select(ctrl->s + 1, &rfds, NULL, NULL, &tv);
        if (FD_ISSET(ctrl->s, &rfds)) {
            res = recv(ctrl->s, reply, *reply_len, 0);
            if (res < 0)
                return res;
            if (res > 0 && reply[0] == '<') {
                /* This is an unsolicited message from
                 * wpa_supplicant, not the reply to the
                 * request. Use msg_cb to report this to the
                 * caller. */
                if (msg_cb) {
                    /* Make sure the message is nul
                     * terminated. */
                    if ((size_t) res == *reply_len)
                        res = (*reply_len) - 1;
                    reply[res] = '\0';
                    msg_cb(reply, res);
                }
                continue;
            }
            *reply_len = res;
            break;
        } else {
            return -2;
        }
    }
    return 0;
}
#endif /* CTRL_IFACE_SOCKET */


static int wpa_ctrl_attach_helper(struct wpa_ctrl *ctrl, int attach)
{
    char buf[10];
    int ret;
    size_t len = 10;

    ret = wpa_ctrl_request(ctrl, attach ? "ATTACH" : "DETACH", 6,
            buf, &len, NULL);
    if (ret < 0)
        return ret;
    if (len == 3 && os_memcmp(buf, "OK\n", 3) == 0)
        return 0;
    return -1;
}


int wpa_ctrl_attach(struct wpa_ctrl *ctrl)
{
    return wpa_ctrl_attach_helper(ctrl, 1);
}


int wpa_ctrl_detach(struct wpa_ctrl *ctrl)
{
    return wpa_ctrl_attach_helper(ctrl, 0);
}


#ifdef CTRL_IFACE_SOCKET

int wpa_ctrl_recv(struct wpa_ctrl *ctrl, char *reply, size_t *reply_len)
{
    int res;

    res = recv(ctrl->s, reply, *reply_len, 0);
    if (res < 0)
        return res;
    *reply_len = res;
    return 0;
}


int wpa_ctrl_pending(struct wpa_ctrl *ctrl)
{
    struct timeval tv;
    fd_set rfds;
    tv.tv_sec = 0;
    tv.tv_usec = 0;
    FD_ZERO(&rfds);
    FD_SET(ctrl->s, &rfds);
    select(ctrl->s + 1, &rfds, NULL, NULL, &tv);
    return FD_ISSET(ctrl->s, &rfds);
}


int wpa_ctrl_get_fd(struct wpa_ctrl *ctrl)
{
    return ctrl->s;
}

#endif /* CTRL_IFACE_SOCKET */


#ifdef CONFIG_CTRL_IFACE_NAMED_PIPE

#ifndef WPA_SUPPLICANT_NAMED_PIPE
#define WPA_SUPPLICANT_NAMED_PIPE "WpaSupplicant"
#endif
#define NAMED_PIPE_PREFIX TEXT("\\\\.\\pipe\\") TEXT(WPA_SUPPLICANT_NAMED_PIPE)

struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
{
    struct wpa_ctrl *ctrl;
    DWORD mode;
    TCHAR name[256];
    int i, ret;

    ctrl = os_malloc(sizeof(*ctrl));
    if (ctrl == NULL)
        return NULL;
    os_memset(ctrl, 0, sizeof(*ctrl));

#ifdef UNICODE
    if (ctrl_path == NULL)
        ret = _snwprintf(name, 256, NAMED_PIPE_PREFIX);
    else
        ret = _snwprintf(name, 256, NAMED_PIPE_PREFIX TEXT("-%S"),
                ctrl_path);
#else /* UNICODE */
    if (ctrl_path == NULL)
        ret = os_snprintf(name, 256, NAMED_PIPE_PREFIX);
    else
        ret = os_snprintf(name, 256, NAMED_PIPE_PREFIX "-%s",
                ctrl_path);
#endif /* UNICODE */
    if (ret < 0 || ret >= 256) {
        os_free(ctrl);
        return NULL;
    }

    for (i = 0; i < 10; i++) {
        ctrl->pipe = CreateFile(name, GENERIC_READ | GENERIC_WRITE, 0,
                NULL, OPEN_EXISTING, 0, NULL);
        /*
         * Current named pipe server side in wpa_supplicant is
         * re-opening the pipe for new clients only after the previous
         * one is taken into use. This leaves a small window for race
         * conditions when two connections are being opened at almost
         * the same time. Retry if that was the case.
         */
        if (ctrl->pipe != INVALID_HANDLE_VALUE ||
                GetLastError() != ERROR_PIPE_BUSY)
            break;
        WaitNamedPipe(name, 1000);
    }
    if (ctrl->pipe == INVALID_HANDLE_VALUE) {
        os_free(ctrl);
        return NULL;
    }

    mode = PIPE_READMODE_MESSAGE;
    if (!SetNamedPipeHandleState(ctrl->pipe, &mode, NULL, NULL)) {
        CloseHandle(ctrl->pipe);
        os_free(ctrl);
        return NULL;
    }

    return ctrl;
}


void wpa_ctrl_close(struct wpa_ctrl *ctrl)
{
    CloseHandle(ctrl->pipe);
    os_free(ctrl);
}


int wpa_ctrl_request(struct wpa_ctrl *ctrl, const char *cmd, size_t cmd_len,
        char *reply, size_t *reply_len,
        void (*msg_cb)(char *msg, size_t len))
{
    DWORD written;
    DWORD readlen = *reply_len;

    if (!WriteFile(ctrl->pipe, cmd, cmd_len, &written, NULL))
        return -1;

    if (!ReadFile(ctrl->pipe, reply, *reply_len, &readlen, NULL))
        return -1;
    *reply_len = readlen;

    return 0;
}


int wpa_ctrl_recv(struct wpa_ctrl *ctrl, char *reply, size_t *reply_len)
{
    DWORD len = *reply_len;
    if (!ReadFile(ctrl->pipe, reply, *reply_len, &len, NULL))
        return -1;
    *reply_len = len;
    return 0;
}


int wpa_ctrl_pending(struct wpa_ctrl *ctrl)
{
    DWORD left;

    if (!PeekNamedPipe(ctrl->pipe, NULL, 0, NULL, &left, NULL))
        return -1;
    return left ? 1 : 0;
}


int wpa_ctrl_get_fd(struct wpa_ctrl *ctrl)
{
    return -1;
}

#endif /* CONFIG_CTRL_IFACE_NAMED_PIPE */

#endif /* CONFIG_CTRL_IFACE */
